Global of personal computers will be cannibalized by the onset of tablets and other devices in the next few years, but two leading technology research groups differ on how bad the damage will be.

International Data Corp. sees a 1.3 percent drop in PC sales this year following a disappointing third quarter of 2012 that saw a 3.7 percent drop, despite the holiday season launch of Microsoft's Windows 8 operating system.

Gartner Research predicts a more substantial 7.6 percent drop in PC sales because of the proliferation of lower-priced tablets. But both agree on one thing: The numbers aren't likely to get better.

Rather than a temporary economic trend, the numbers reflect a long-term change in user behavior, Gartner said.

Changing Behavior

"While there will be some individuals who retain both a personal PC and a tablet, especially those who use either or both for work and play, most will be satisfied with the experience they get from a tablet as their main computing device," said Carolina Milanesi, research vice president for Gartner, in a statement. "As consumers shift their time away from their PC to tablets and smartphones, they will no longer see their PC as a device that they need to replace on a regular basis."

Gartner sees desktop and laptop PC shipments falling from more than 341 million this year to under 272 million in 2017, while tablets will surge from more than 116 million to a mind-blowing 467 million-plus in 2017.

IDC sees overall PC shipments rising from 350 million last year to 382 million in 2017, with desktop computers taking the biggest hit, from 148 million to 141 million, while portable PCs could grow from 202 million to 241 million.

"The PC market is still looking for updated models to gain traction and demonstrate sufficient appeal to drive growth in a very competitive market," said Loren Loverde, program vice president for Worldwide PC Trackers at IDC.

Shipments would increase in emerging markets, from just under 206 million to 240 million in the next four years, IDC said, while mature markets would see a slight drop from 145 million from just shy of 142 million.

The picture painted by Gartner is particularly rosy for devices powered by Google's Android, with worldwide shipments expected to grow from more than 497 million this year to more than 1.4 billion in 2017. Apple's iOS devices will surge from 212 million this year to more than 504 million in that time span, while Windows device shipments could grow from more than 346 million to almost 571 million.

BlackBerry Sours

In contrast, the future is bleak for BlackBerry devices. Shipments are projected by Gartner to drop from 34.7 million to just over 24 million in that time.

Those figures are for notebooks as well as desk-based PCs, tablets, Ultranotebooks and mobile phones.

"The trend towards smartphones and tablets will have much wider implications than hardware displacement," Milanesi said. "Software and chipset architecture are also impacted by this shift as consumers embrace apps and personal cloud."